A flow control mechanism connected to the intake and exhaust systems of an engine. The mechanism may achieve recirculation of exhaust gases despite varying differential pressures or delta pressures between the systems, particularly since intake pressures may often exceed exhaust pressures. Pressure sensors may be situated proximate to the input and output of the flow control mechanism. There may a flow sensor proximate to the flow control mechanism. Cylinder pressure or pulse sensors may be situated in or about the engine. A processor may be connected to various sensors and provide prompt active control of a valve or like device in the flow control mechanism. Such valve may operate sufficiently quickly so as to prevent backflow from the intake system into the exhaust system upon sudden pressure changes in the systems. The quickness of the active valve control may also permit recirculating stipulated amounts of exhaust gas to each cylinder.